4d37e7e3fd
i386 inline assembler cleanup. This change encapsulates descriptor and task register management. Also, it is possible to improve assembler generation in two cases; savesegment may store the value in a register instead of a memory location, which allows GCC to optimize stack variables into registers, and MOV MEM, SEG is always a 16-bit write to memory, making the casting in math-emu unnecessary. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
66 lines
1.6 KiB
C
66 lines
1.6 KiB
C
#include <linux/mm.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/init.h>
|
|
#include <linux/init_task.h>
|
|
#include <linux/fs.h>
|
|
|
|
#include <asm/uaccess.h>
|
|
#include <asm/pgtable.h>
|
|
#include <asm/processor.h>
|
|
#include <asm/desc.h>
|
|
|
|
#define DOUBLEFAULT_STACKSIZE (1024)
|
|
static unsigned long doublefault_stack[DOUBLEFAULT_STACKSIZE];
|
|
#define STACK_START (unsigned long)(doublefault_stack+DOUBLEFAULT_STACKSIZE)
|
|
|
|
#define ptr_ok(x) ((x) > PAGE_OFFSET && (x) < PAGE_OFFSET + 0x1000000)
|
|
|
|
static void doublefault_fn(void)
|
|
{
|
|
struct Xgt_desc_struct gdt_desc = {0, 0};
|
|
unsigned long gdt, tss;
|
|
|
|
store_gdt(&gdt_desc);
|
|
gdt = gdt_desc.address;
|
|
|
|
printk("double fault, gdt at %08lx [%d bytes]\n", gdt, gdt_desc.size);
|
|
|
|
if (ptr_ok(gdt)) {
|
|
gdt += GDT_ENTRY_TSS << 3;
|
|
tss = *(u16 *)(gdt+2);
|
|
tss += *(u8 *)(gdt+4) << 16;
|
|
tss += *(u8 *)(gdt+7) << 24;
|
|
printk("double fault, tss at %08lx\n", tss);
|
|
|
|
if (ptr_ok(tss)) {
|
|
struct tss_struct *t = (struct tss_struct *)tss;
|
|
|
|
printk("eip = %08lx, esp = %08lx\n", t->eip, t->esp);
|
|
|
|
printk("eax = %08lx, ebx = %08lx, ecx = %08lx, edx = %08lx\n",
|
|
t->eax, t->ebx, t->ecx, t->edx);
|
|
printk("esi = %08lx, edi = %08lx\n",
|
|
t->esi, t->edi);
|
|
}
|
|
}
|
|
|
|
for (;;) /* nothing */;
|
|
}
|
|
|
|
struct tss_struct doublefault_tss __cacheline_aligned = {
|
|
.esp0 = STACK_START,
|
|
.ss0 = __KERNEL_DS,
|
|
.ldt = 0,
|
|
.io_bitmap_base = INVALID_IO_BITMAP_OFFSET,
|
|
|
|
.eip = (unsigned long) doublefault_fn,
|
|
.eflags = X86_EFLAGS_SF | 0x2, /* 0x2 bit is always set */
|
|
.esp = STACK_START,
|
|
.es = __USER_DS,
|
|
.cs = __KERNEL_CS,
|
|
.ss = __KERNEL_DS,
|
|
.ds = __USER_DS,
|
|
|
|
.__cr3 = __pa(swapper_pg_dir)
|
|
};
|